[1/4] Participants take part in the Beijing Marathon, at Tiananmen Square in Beijing, China October 29, 2023. REUTERS/Tingshu Wang Acquire Licensing RightsBEIJING, Oct 29 (Reuters) - Runners undeterred by thick smog engulfing the Chinese capital ran the Beijing Marathon maskless on Sunday, many wearing shorts in one of the warmest Octobers on record. Beijing was the fourth most-polluted major city in the world on Sunday, according to Swiss air-quality technology firm IQAir. Beijing's high on Sunday was 19 C (66 F), according to the national weather bureau. The weather bureau forecast weak cold air currents to last the rest of the month before beginning to cool in early November.

---

Persons: Tingshu Wang, Fang Chong, Liz Lee, Ryan Woo, Han Xiao, Bernard Orr, William Mallard Organizations: Beijing, REUTERS, Rights, Beijing Marathon, Meteorological Centre, Thomson Locations: Beijing, China, Rights BEIJING, Tiananmen, Haidian, Beijing's, Tangshan, Handan, Hebei